512 lines
16 KiB
C#
512 lines
16 KiB
C#
using NBF;
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using UnityEngine;
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[RequireComponent(typeof(LineRenderer))]
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public class Rope : MonoBehaviour
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{
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[Header("Anchors")] [SerializeField] public Rigidbody startAnchor;
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[SerializeField] public Rigidbody endAnchor;
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[Header("Physics (Dynamic Nodes, Fixed Segment Len)")] [SerializeField, Min(0.01f), Tooltip("物理每段固定长度（越小越细致越耗）")]
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private float physicsSegmentLen = 0.15f;
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[SerializeField, Range(2, 200)] private int minPhysicsNodes = 12;
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[SerializeField, Range(2, 400)] [Tooltip("物理节点上限（仅用于性能保护；与“最大长度不限制”不是一回事）")]
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private int maxPhysicsNodes = 120;
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[SerializeField] private float gravityStrength = 2.0f;
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[SerializeField, Range(0f, 1f)] private float velocityDampen = 0.95f;
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[SerializeField, Range(0.0f, 1.0f)] [Tooltip("约束修正强度，越大越硬。0.6~0.9 常用")]
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private float stiffness = 0.8f;
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[SerializeField, Range(1, 80)] [Tooltip("迭代次数。鱼线 10~30 通常够用")]
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private int iterations = 20;
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[Header("Length Control (No Min/Max Clamp)")]
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[Tooltip("初始总长度（米）。如果为 0，则用 physicsSegmentLen*(minPhysicsNodes-1) 作为初始长度")]
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[SerializeField, Min(0f)]
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private float initialLength = 0f;
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[Tooltip("长度变化平滑时间（越小越跟手，越大越稳）")] [SerializeField, Min(0.0001f)]
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private float lengthSmoothTime = 0.15f;
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[Tooltip("当长度在变化时，额外把速度压掉一些（防抖）。0=不额外处理，1=变化时几乎清速度")] [SerializeField, Range(0f, 1f)]
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private float lengthChangeVelocityKill = 0.6f;
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[Tooltip("允许的最小松弛余量（避免目标长度刚好等于锚点距离时抖动）")] [SerializeField, Min(0f)]
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private float minSlack = 0.002f;
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[Header("Head Segment Clamp")] [Tooltip("第一段（起点->第1节点）允许的最小长度，避免收线时第一段被压到0导致数值炸")] [SerializeField, Min(0.0001f)]
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private float headMinLen = 0.01f;
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[Header("Simple Ground/Water Constraint (Cheap)")] [SerializeField]
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private bool constrainToGround = true;
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[SerializeField] private LayerMask groundMask = ~0;
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[SerializeField, Min(0f)] private float groundRadius = 0.01f;
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[SerializeField, Min(0f)] private float groundCastHeight = 1.0f;
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[SerializeField, Min(0.01f)] private float groundCastDistance = 2.5f;
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[SerializeField] private bool constrainToWater = false;
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[SerializeField] private float waterHeight = 0f;
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[SerializeField, Min(0f)] private float waterRadius = 0.01f;
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[Header("Render (High Resolution)")] [SerializeField, Min(1), Tooltip("每段物理线段插值加密的数量（越大越顺，越耗）")]
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private int renderSubdivisions = 6;
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[SerializeField, Tooltip("是否使用 Catmull-Rom 平滑（推荐开启）")]
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private bool smooth = true;
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[SerializeField, Min(0.0001f)] private float lineWidth = 0.002f;
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private LineRenderer lr;
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// physics
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private int physicsNodes;
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private Vector3[] pCurr;
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private Vector3[] pPrev;
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// render
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private Vector3[] rPoints;
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private int rCountCached = -1;
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private Vector3 gravity;
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// length control runtime
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private float targetLength;
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private float currentLength;
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private float lengthSmoothVel;
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// Only-head-change trick:
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// Total rest length = headRestLen + (physicsNodes - 2) * physicsSegmentLen
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private float headRestLen;
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private void Awake()
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{
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lr = GetComponent<LineRenderer>();
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gravity = new Vector3(0f, -gravityStrength, 0f);
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InitLengthSystem();
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AllocateAndInitNodes();
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RebuildRenderBufferIfNeeded();
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}
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private FRod _rod;
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public void Init(FRod rod)
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{
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_rod = rod;
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}
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private void OnValidate()
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{
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renderSubdivisions = Mathf.Max(renderSubdivisions, 1);
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iterations = Mathf.Clamp(iterations, 1, 80);
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groundCastDistance = Mathf.Max(groundCastDistance, 0.01f);
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groundCastHeight = Mathf.Max(groundCastHeight, 0f);
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lineWidth = Mathf.Max(lineWidth, 0.0001f);
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lengthSmoothTime = Mathf.Max(lengthSmoothTime, 0.0001f);
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physicsSegmentLen = Mathf.Max(physicsSegmentLen, 0.01f);
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minPhysicsNodes = Mathf.Max(minPhysicsNodes, 2);
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maxPhysicsNodes = Mathf.Max(maxPhysicsNodes, minPhysicsNodes);
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headMinLen = Mathf.Max(headMinLen, 0.0001f);
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}
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private void InitLengthSystem()
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{
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// 没有 min/max 长度限制：初始长度只做一个“非负”保障
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float defaultLen = physicsSegmentLen * (Mathf.Max(minPhysicsNodes, 2) - 1);
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currentLength = (initialLength > 0f) ? initialLength : defaultLen;
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targetLength = currentLength;
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}
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private void AllocateAndInitNodes()
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{
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// 若锚点存在：最小长度就是两锚点直线距离 + minSlack（防抖）
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if (startAnchor && endAnchor)
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{
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float minFeasible = Vector3.Distance(startAnchor.position, endAnchor.position) + minSlack;
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currentLength = Mathf.Max(currentLength, minFeasible);
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targetLength = Mathf.Max(targetLength, minFeasible);
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}
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physicsNodes = Mathf.Clamp(ComputeDesiredNodes(currentLength), 2, maxPhysicsNodes);
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pCurr = new Vector3[physicsNodes];
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pPrev = new Vector3[physicsNodes];
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// 初始从起点往下排
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Vector3 start = startAnchor ? startAnchor.position : transform.position;
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Vector3 dir = Vector3.down;
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for (int i = 0; i < physicsNodes; i++)
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{
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Vector3 pos = start + dir * (physicsSegmentLen * i);
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pCurr[i] = pos;
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pPrev[i] = pos;
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}
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UpdateHeadRestLenFromCurrentLength();
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if (startAnchor && endAnchor)
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LockAnchorsHard();
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}
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private int ComputeDesiredNodes(float lengthMeters)
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{
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// nodes = floor(length/segLen)+1
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int desired = Mathf.FloorToInt(Mathf.Max(0f, lengthMeters) / physicsSegmentLen) + 1;
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desired = Mathf.Clamp(desired, minPhysicsNodes, maxPhysicsNodes);
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return desired;
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}
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/// <summary>设置目标总长度（米）。不做最小/最大长度限制（最小可行由锚点距离决定）。</summary>
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public void SetTargetLength(float lengthMeters)
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{
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targetLength = Mathf.Max(0f, lengthMeters);
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}
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/// <summary>增加/减少目标总长度（米）。正数放线，负数收线。</summary>
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public void AddTargetLength(float deltaMeters)
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{
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SetTargetLength(targetLength + deltaMeters);
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}
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public float GetCurrentLength() => currentLength;
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public float GetTargetLength() => targetLength;
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public float GetAnchorDistance()
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{
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if (startAnchor != null && endAnchor != null)
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{
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return Vector3.Distance(startAnchor.position, endAnchor.position);
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}
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return 0;
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}
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private void FixedUpdate2()
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{
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if (!startAnchor || !endAnchor)
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return;
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gravity.y = -gravityStrength;
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UpdateLengthSmooth(); // 只保证 >= 锚点直线距离 + minSlack
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UpdateNodesFromLength(); // 只从头部增/减节点
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UpdateHeadRestLenFromCurrentLength(); // 第一段补余量 => 变化集中在头部
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Simulate();
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for (int it = 0; it < iterations; it++)
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{
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SolveDistanceConstraints_HeadOnly();
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LockAnchorsHard();
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}
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if (constrainToWater || constrainToGround)
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ConstrainToGroundAndWater();
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LockAnchorsHard();
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}
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private void LateUpdate()
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{
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DrawHighResLine();
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FixedUpdate2();
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}
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private void UpdateLengthSmooth()
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{
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float anchorDist = Vector3.Distance(startAnchor.position, endAnchor.position);
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float minFeasible = anchorDist + minSlack;
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// ✅ 最小长度 = 起点终点直线距离(+slack)，最大不限制
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float desired = Mathf.Max(targetLength, minFeasible);
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float prevLen = currentLength;
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currentLength = Mathf.SmoothDamp(
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currentLength,
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desired,
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ref lengthSmoothVel,
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lengthSmoothTime,
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Mathf.Infinity,
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Time.fixedDeltaTime
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);
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float lenDelta = Mathf.Abs(currentLength - prevLen);
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if (lenDelta > 1e-5f && lengthChangeVelocityKill > 0f && pPrev != null)
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{
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float kill = Mathf.Clamp01(lengthChangeVelocityKill);
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for (int i = 1; i < physicsNodes - 1; i++)
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pPrev[i] = Vector3.Lerp(pPrev[i], pCurr[i], kill);
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}
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}
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private void UpdateNodesFromLength()
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{
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int desired = ComputeDesiredNodes(currentLength);
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if (desired == physicsNodes) return;
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while (physicsNodes < desired)
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AddNodeAtStart();
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while (physicsNodes > desired)
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RemoveNodeAtStart();
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RebuildRenderBufferIfNeeded();
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}
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private void AddNodeAtStart()
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{
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int newCount = Mathf.Min(physicsNodes + 1, maxPhysicsNodes);
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if (newCount == physicsNodes) return;
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Vector3[] newCurr = new Vector3[newCount];
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Vector3[] newPrev = new Vector3[newCount];
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newCurr[0] = pCurr[0];
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newPrev[0] = pPrev[0];
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for (int i = 2; i < newCount; i++)
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{
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newCurr[i] = pCurr[i - 1];
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newPrev[i] = pPrev[i - 1];
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}
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Vector3 s = startAnchor.position;
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Vector3 dir = Vector3.down;
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if (physicsNodes >= 2)
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{
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Vector3 toOld1 = (pCurr[1] - s);
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if (toOld1.sqrMagnitude > 1e-6f) dir = toOld1.normalized;
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}
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Vector3 pos = s + dir * physicsSegmentLen;
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newCurr[1] = pos;
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newPrev[1] = pos;
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pCurr = newCurr;
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pPrev = newPrev;
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physicsNodes = newCount;
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LockAnchorsHard();
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}
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private void RemoveNodeAtStart()
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{
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int newCount = Mathf.Max(physicsNodes - 1, 2);
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if (newCount == physicsNodes) return;
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Vector3[] newCurr = new Vector3[newCount];
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Vector3[] newPrev = new Vector3[newCount];
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newCurr[0] = pCurr[0];
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newPrev[0] = pPrev[0];
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for (int i = 1; i < newCount - 1; i++)
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{
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newCurr[i] = pCurr[i + 1];
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newPrev[i] = pPrev[i + 1];
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}
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newCurr[newCount - 1] = pCurr[physicsNodes - 1];
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newPrev[newCount - 1] = pPrev[physicsNodes - 1];
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pCurr = newCurr;
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pPrev = newPrev;
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physicsNodes = newCount;
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LockAnchorsHard();
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}
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private void UpdateHeadRestLenFromCurrentLength()
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{
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int fixedSegCount = Mathf.Max(0, physicsNodes - 2);
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float baseLen = fixedSegCount * physicsSegmentLen;
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headRestLen = currentLength - baseLen;
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// 第一段允许在一个合理范围内变动（太长会像橡皮筋，太短会炸）
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headRestLen = Mathf.Clamp(headRestLen, headMinLen, physicsSegmentLen * 1.5f);
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}
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private void Simulate()
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{
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float dt = Time.fixedDeltaTime;
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for (int i = 0; i < physicsNodes; i++)
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{
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Vector3 v = (pCurr[i] - pPrev[i]) * velocityDampen;
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pPrev[i] = pCurr[i];
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pCurr[i] += v;
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pCurr[i] += gravity * dt;
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}
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LockAnchorsHard();
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}
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private void LockAnchorsHard()
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{
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if (!startAnchor || !endAnchor || pCurr == null || pPrev == null || physicsNodes < 2) return;
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float dt = Time.fixedDeltaTime;
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Vector3 s = startAnchor.position;
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Vector3 e = endAnchor.position;
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pCurr[0] = s;
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pPrev[0] = s - startAnchor.linearVelocity * dt;
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int last = physicsNodes - 1;
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pCurr[last] = e;
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pPrev[last] = e - endAnchor.linearVelocity * dt;
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}
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private void SolveDistanceConstraints_HeadOnly()
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{
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for (int i = 0; i < physicsNodes - 1; i++)
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{
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float rest = (i == 0) ? headRestLen : physicsSegmentLen;
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Vector3 a = pCurr[i];
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Vector3 b = pCurr[i + 1];
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Vector3 delta = b - a;
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float dist = delta.magnitude;
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if (dist < 1e-6f) continue;
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float diff = (dist - rest) / dist;
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Vector3 corr = delta * diff * stiffness;
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if (i != 0)
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pCurr[i] += corr * 0.5f;
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if (i + 1 != physicsNodes - 1)
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pCurr[i + 1] -= corr * 0.5f;
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}
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}
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private void ConstrainToGroundAndWater()
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{
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for (int i = 1; i < physicsNodes - 1; i++)
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{
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Vector3 p = pCurr[i];
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if (constrainToWater)
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{
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float minY = waterHeight + waterRadius;
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if (p.y < minY) p.y = minY;
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}
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if (constrainToGround)
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{
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Vector3 origin = p + Vector3.up * groundCastHeight;
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if (Physics.Raycast(origin, Vector3.down, out RaycastHit hit, groundCastDistance, groundMask,
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QueryTriggerInteraction.Ignore))
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{
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float minY = hit.point.y + groundRadius;
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if (p.y < minY) p.y = minY;
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}
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}
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pCurr[i] = p;
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}
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}
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private void DrawHighResLine()
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{
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if (pCurr == null || physicsNodes < 2) return;
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RebuildRenderBufferIfNeeded();
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lr.startWidth = lineWidth;
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lr.endWidth = lineWidth;
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if (!smooth)
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{
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lr.positionCount = physicsNodes;
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lr.SetPositions(pCurr);
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return;
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}
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int idx = 0;
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for (int seg = 0; seg < physicsNodes - 1; seg++)
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{
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Vector3 p0 = pCurr[Mathf.Max(seg - 1, 0)];
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Vector3 p1 = pCurr[seg];
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Vector3 p2 = pCurr[seg + 1];
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Vector3 p3 = pCurr[Mathf.Min(seg + 2, physicsNodes - 1)];
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for (int s = 0; s < renderSubdivisions; s++)
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{
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float t = s / (float)renderSubdivisions;
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Vector3 pt = CatmullRom_XZ_LinearY(p0, p1, p2, p3, t);
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// 如果水面约束开启：渲染点也夹一下，避免视觉上又穿回去
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if (constrainToWater)
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{
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float minY = waterHeight + waterRadius;
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if (pt.y < minY) pt.y = minY;
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}
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rPoints[idx++] = pt;
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}
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}
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rPoints[idx++] = pCurr[physicsNodes - 1];
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lr.positionCount = idx;
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lr.SetPositions(rPoints);
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}
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private void RebuildRenderBufferIfNeeded()
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{
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int targetCount = (physicsNodes - 1) * renderSubdivisions + 1;
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if (rPoints == null || rCountCached != targetCount)
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{
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rPoints = new Vector3[targetCount];
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rCountCached = targetCount;
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}
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}
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private static Vector3 CatmullRom(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
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{
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float t2 = t * t;
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float t3 = t2 * t;
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return 0.5f * (
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(2f * p1) +
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(-p0 + p2) * t +
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(2f * p0 - 5f * p1 + 4f * p2 - p3) * t2 +
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(-p0 + 3f * p1 - 3f * p2 + p3) * t3
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);
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}
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private void OnDrawGizmosSelected()
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{
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if (pCurr == null) return;
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Gizmos.color = Color.yellow;
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for (int i = 0; i < pCurr.Length; i++)
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Gizmos.DrawSphere(pCurr[i], 0.01f);
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}
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private static Vector3 CatmullRom_XZ_LinearY(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
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{
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// XZ 做 Catmull-Rom
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Vector3 cr = CatmullRom(p0, p1, p2, p3, t);
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// Y 不做样条，改成线性（不会过冲）
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cr.y = Mathf.Lerp(p1.y, p2.y, t);
|
||
|
||
return cr;
|
||
}
|
||
} |